Version 11.6, 2011-07-01
Abstract
These release notes apply to all SUSE Linux Enterprise High Availability 11 Service Pack 2 based products (e.g. for
x86, x86_64, Itanium, Power and System z). Some
sections may not apply to a particular architecture/product. Where this is
not obvious, the respective architectures are listed explicitly in these notes.
Instructions for installing SUSE Linux Enterprise High Availability 11 Service Pack 2 can be found in the
README file on the CD.
Manuals can be found in the docu directory of the
installation media. Any documentation (if installed) can be found in the
/usr/share/doc/ directory of the installed system.
This Novell product includes materials licensed to Novell under the GNU General Public License (GPL). The GPL requires that Novell make available certain source code that corresponds to those GPL-licensed materials. The source code is available for download at http://www.novell.com/linux/source. Also, for up to three years from Novell's distribution of the Novell product, Novell will mail a copy of the source code upon request. Requests should be sent by e-mail to sle_source_request@novell.com or as otherwise instructed at http://www.novell.com/linux/source. Novell may charge a fee to recover its reasonable costs of distribution.
SUSE Linux Enterprise High Availability 11 Service Pack 2 is an affordable, integrated suite of robust open source clustering technologies that enable enterprises to implement highly available Linux clusters and eliminate single points of failure.
Used with SUSE Linux Enterprise Server 11 SP2, it helps firms maintain business continuity, protect data integrity, and reduce unplanned downtime for their mission-critical Linux workloads.
SUSE Linux Enterprise High Availability 11 Service Pack 2 provides all of the essential monitoring, messaging, and cluster resource management functionality of proprietary third-party solutions, but at a more affordable price, making it accessible to a wider range of enterprises.
It is optimized to work with SUSE Linux Enterprise Server 11 SP2, and its tight integration ensures customers have the most robust, secure, and up to date high availability solution. Based on an innovative, highly flexible policy engine, it supports a wide range of clustering scenarios.
With static or stateless content, the High Availability cluster can be used without a cluster file system. This includes web-services with static content as well as printing systems or communication systems like proxies that do not need to recover data.
Finally, it's open source license minimizes the risk of vendor lock-in, and it's adherence to open standards encourages interoperability with industry standard tools and technologies.
In Service Pack 2, a large number of improvements have been added, some of which are called out explicitly here. For the full list of changes and bugfixes, please refer to the change logs of the RPM packages. Note that these changes are in addition to those that have already been added via Service Pack 1.
This section includes an overview of some of the major features and new functionality provided by SUSE Linux Enterprise High Availability 11 Service Pack 2.
Cluster File System - Oracle Cluster File System 2 (OCFS2)
Cluster file systems are used to provide scalable, high performance, and highly available file access across multiple instances of SUSE Linux Enterprise High Availability 11 Service Pack 2 servers. Oracle Cluster File System 2 (OCFS2) is a POSIX-compliant shared-disk cluster file system for Linux. OCFS2 is developed under a GPL open source license.
New features included in OCFS2 with this product release are:
Support for repquota has been added.
Beyond this, OCFS2 continues to deliver the functionality provided in the previous releases:
indexed directories, delivering high performance regardless of number of files per directory
Meta data checksumming, detects all on-disk corruption and capable of correcting some errors transparently
Improved performance for deletion
Improved allocation algorithms reduce fragmentation for large files
Access Control Lists (ACL)
Quota support
POSIX conforming file locking
expand file system during operation
With these features OCFS2 can be used as generic file system for common use without previous limitations to specific workloads. Workloads for OCFS2 included in this product are, but are not limited to:
central storage area for virtual machine images
central storage area for file servers
shared file system for High Availability
Oracle Database
all applications using a cluster file system (e.g. Tibco)
The full functionality of OCFS2 is only available in combination with the OpenAIS, corosync, and Pacemaker-based cluster stack.
Clustered Logical Volume Manager2 - cLVM2
The Clustered Volume Manager allows multiple nodes to read and write volumes on a single storage device at the block layer level. It features creation and reallocation of volumes on a shared storage infrastructure like SAN or iSCSI, and allows moving volumes to a different storage device during operation. It can be used for volume snapshots for later recovery if needed.
cLVM2 has been updated to the latest upstream version.
High Availability Cluster Resource Manager (Pacemaker)
Pacemaker orchestrates the cluster's response to change events such as node failures, resource monitoring failures, permanent or transient administrative changes, and ensures that service availability is recovered.
New features introduced by Pacemaker and included with this product release are:
Dynamic utilization-based resource placement
A powerful web console (hawk) for management and monitoring
hawk has been enhanced to support full cluster administration, including access control lists, the cluster test drive, and a new graphical history explorer.
hawk now supports an extensible UI wizard with a set of templates already included that can be used to guide users through standard set up tasks.
Support for resource templates to simplify and reduce CIB complexity
Log file query tools available from the commandline shell. The CIB now also records the source and user of a given change to ease history analysis.
Passwords can now be saved external to the CIB for secure storage.
The number of concurrent live migrations can now be limited to avoid overloading node capacity.
The CIB now supports cluster-wide, in addition to node, attributes.
With unified command line support system setup, managing and integration is made easier. To extend High Availability to all types of applications, resource agent templates and templates for configuration examples are provided for customization.
Cluster and Distributed Systems infrastructure (corosync and OpenAIS
The Corosync Cluster Engine is an OSI certified implementation of a complete cluster engine. This component provides membership, ordered messaging with virtual synchrony guarantees, closed process communication groups, and an extensible framework.
Support unicast communication in addition to multicast and broadcast, with full YaST2 support.
Data replication - Distributed Remote Block Device (DRBD)
Data replication is part of a disaster prevention strategy in most large enterprises. Using network connections data is replicated between different nodes to ensure consistent data storages in case of a site failure.
Data replication is provided in SUSE Linux Enterprise High Availability 11 Service Pack 2 with DRBD. This software based data replication allows customers to use different types of storage systems and communication layers without vendor lock-in. At the same time, data replication is deeply integrated into the operating system and thus provide ease-of-use. Features related to data replication and included with this product release are:
YaST2 setup tools to assist initial setup
Fully synchronous, memory synchronous or asynchronous modes of operation
Differential storage resynchronization after failure
Bandwidth of background resynchronization tunable
Shared secret to authenticate the peer upon connect
Configurable handler scripts for various DRBD events
Online data verification
With these features data replication can be easier configured and used. And with improved storage resynchronization recovery times will be decreased significantly.
The distributed replicated block device (DRBD) version included supports active/active mirroring, enabling the use of services such as cLVM2 or OCFS2 on top.
IP Load Balancing - Linux Virtual Server (LVS)
Linux Virtual Server (LVS) is an advanced IP load balancing solution for Linux. IP load balancing provides a high-performance, scalable network infrastructure. Such infrastructure is typically used by enterprise customers for webservers or other network related service workloads.
With LVS network requests can be spread over multiple nodes to scale the available resources and balance the resulting workload. By monitoring the compute nodes, LVS can handle node failures and redirect requests to other nodes maintaining the availability of the service.
Relax and Recover (ReaR)
New in SUSE Linux Enterprise High Availability 11 Service Pack 2
On the x86 and x86-64 architectures, a disaster recovery framework is included. ReaR allows the administrator to take a full snaphot of the system and restore this snapshot after a disaster on recovery hardware.
Distributed Lock Manager (DLM)
The DLM in SUSE Linux Enterprise High Availability 11 Service Pack 2 supports both TCP and SCTP for network communications, allowing for improved cluster redundancy in scenarios where network interface bonding is not feasible.
pacemaker-pygui rename and split
In response to customer demand, the Python-based GUI component (formerly packaged as pacemaker-pygui) has been split into a server and client package, allowing server installs without client software.
The new packages are called pacemaker-mgmt for the server, and pacemaker-mgmt-client for the client.
After an update from GA, the client package may not
automatically be installed, depending on installer settings, and thus
the hb_gui and crm_gui
commands unavailable.
The resolution is to install the package manually.
New packages from SP2 not installed automatically on update
New functionality provided via new packages is not automatically installed by an update, which strives to preserve the existing functionality. It is recommended to install the HA pattern manually to take advantage of all new functionality in SUSE Linux Enterprise High Availability 11 Service Pack 2.
Non-production fencing/STONITH agents moved
The ssh, external/ssh, and
null STONITH agents have been moved to
the libglue-devel package, and are no longer
installed by default.
These fencing agents are not suitable for production environments and should only be used for limited functionality demo setups. This move clarifies their intended use case.
OCFS2's O2CB stack.
The legacy O2CB in-kernel stack of OCFS2 is only supported in combination with Oracle RAC. Oracle RAC, due to its technical limitations, cannot be combined with the pacemaker-based cluster stack.
Samba Clustered Trivial Database (CTDB)
SUSE Linux Enterprise High Availability 11 Service Pack 2 includes the Samba CTDB extension, including an OCF-compliant resource agent to orchestrate fail-over. This is fully supported, together with exporting Samba CTDB from OCFS2.
Due to technical limitations, this also includes the CTDB internal fail-over functionality for IP address take-over. Please note that this part is not supported by Novell. Only Pacemaker clusters are fully supported.
The smb_private_dir parameter for the CTDB resource agent is now deprecated and has been made optional. Existing installations using CTDB should remove this parameter from their configuration at their next convenience.
Several new parameters have been added to the CTDB resource agent in this release - run "crm ra info CTDB" for details. Two of these parameters, ctdb_manages_samba and ctdb_manages_winbind, default to "yes" for compatibility with the previous releases. Existing installations should update their configuration to explicitly set these parameters to "yes", as the defaults will be changed to "no" in a future release.
DRBD resource agent
The new version of DRBD included in SUSE Linux Enterprise High Availability 11 Service Pack 2 also supplies a new, updated Open Clustering Framework resource agent from the provider linbit.
It is recommended that setups are converted from ocf:heartbeat:drbd to use the new ocf:linbit:drbd agent. Some new features, such as dual-primary support for master resources, is only available in the new version.
Heartbeat
Whereas SUSE Linux Enterprise Server 10 clusters utilized heartbeat as the cluster infrastructure layer, providing messaging and membership services, SUSE Linux Enterprise 11 High-Availability Extension uses corosync and openais. heartbeat is no longer included with the product.
Please use the hb2openais.sh tool for migrating
your SUSE Linux Enterprise Server 10 environment to SUSE Linux Enterprise High Availability 11 Service Pack 2.
EVMS2 replaced with LVM2
Since EVMS2 has been depreciated in SUSE Linux Enterprise Server 11 SP2, the clustered extensions are also no longer available in SUSE Linux Enterprise High Availability 11 Service Pack 2. A conversion tool is supplied as part of the lvm2-clvm package. After the conversion, the former C-EVMS2 segments can be used as regular, full-featured LVM2 logical volumes.
For more details, please refer to
/usr/share/doc/packages/lvm2-clvm/README.csm-converter.
The SUSE Linux Enterprise High Availability Extension stack supports a wide range of different cluster topologies.
Local and Metro Area (stretched) clusters are supported as part of a SUSE Linux Enterprise High Availability Extension subscription. Geographical clustering requires an additional Geo Clustering for SUSE Linux Enterprise High Availability Extension subscription.
Local Cluster
In a local cluster environment, all nodes are connected to the same storage network and on the same network segment; redundant network interconnects are provided. Latency is below 1 millisecond, and network bandwidth is at least 1 Gigabit/s.
Cluster storage is fully symmetric on all nodes, either provided via the storage layer itself, mirrored via MD Raid1, cLVM2, or replicated via DRBD.
In a local cluster all nodes run in a single corosync domain, forming a single cluster.
Metro Area Cluster
In a Metro Area cluster, the network segment can be stretched to a maximum latency of 15 milliseconds between any two nodes (approximately 20 miles or 30 kilometers in physical distance), but fully symmetric and meshed network inter-connectivity is required.
Cluster storage is assumed to be fully symmetric as in local deployments.
As a stretched version of the local cluster, all nodes in a Metro Area cluster run in a single corosync domain, forming a single cluster.
Geographical Clustering
A Geo scenario is primarily defined by the network topology; network latency higher than 15 milliseconds, reduced network bandwidth, and not fully interconnected subnets. In these scenarios, each site by itself must satisfy the requirements of and be configured as a local or metropolitan cluster as defined above. A maximum of three sites are then connected via Geo Clustering for SUSE Linux Enterprise High Availability Extension; for this, direct TCP connections between the sites must be possible, and typical latency should not exceed 1 second.
Storage is typically asymmetrically replicated by the storage layer, such as DRBD, MD Raid1, or vendor-specific solutions.
DLM, OCFS2, and cLVM2 are not available across site boundaries.
Linux Virtual Server tunnelling support
The LVS TCP/UDP load balancer currently only works with Direct Routing and NAT setups. IP-over-IP tunnelling forwarding to the real servers does not currently work.
Cluster-concurrent RAID1 resynchronization
To ensure data integrity, a full RAID1 resync is triggered when a device is re-added to the mirror group. This can impact performance, and it is thus advised to use multipath IO to reduce exposure to mirror loss.
Due to the need of the cluster to keep both mirrors uptodate and consistent on all nodes, a mirror failure on one node is treated as if the failure had been observed cluster-wide, evicting the mirror on all nodes. Again, multipath IO is recommended to reduce this risk.
In situations where the primary focus is on redundancy and
not on scale-out, building a storage target node (using
md raid1 in a fail-over configuration or
using drbd) and reexporting via iSCSI, NFS,
or CIFS could be a viable option.
Quotas on OCFS2 filesystem
To use quotas on ocfs2 filesystem, the filesystem has to be created with appropriate quota features: 'usrquota' filesystem feature is needed for accounting quotas for individual users, 'grpquota' filesystem feature is needed for accounting of quotas for groups. These features can be also enabled later on an unmounted filesystem using tunefs.ocfs2.
For quota-tools to operate on the filesystem, you have to mount the filesystem with 'usrquota' (and/or 'grpquota') mount option.
When a filesystem has appropriate quota feature enabled, it maintains in its metadata how much space and files each user (group) uses. Since ocfs2 treats quota information as a filesystem internal metadata, there is no need to ever run quotacheck(8) program. Instead, all the needed functionality is built into fsck.ocfs2 and the filesystem driver itself.
To enable enforcement of limits imposed on each user / group, run quotaon(8) program similarly as for any other filesystem.
Commands quota(1), setquota(8), edquota(8) work as usual with ocfs2 filesystem. Commands repquota(8) and warnquota(8) do not work with ocfs2 because of a limitation in the current kernel interface.
For performance reasons each cluster node performs quota accounting locally and synchronizes this information with a common central storage once per 10 seconds (this interval is tunable by tunefs.ocfs2 using options 'usrquota-sync-interval' and 'grpquota-sync-interval'). Thus quota information need not be exact at all times and as a consequence user / group can slightly exceed their quota limit when operating on several cluster nodes in parallel.
Support requires an appropriate subscription from Novell; for more information, please see: http://www.novell.com/products/server/services_support.html.
A Geo Clustering for SUSE Linux Enterprise High Availability extension subscription is needed to receive support and maintenance to run geographical clustering scenarios, including manual and automated setups.
Support for the DRBD storage replication is independent of the cluster scenario and included as part of the SUSE Linux Enterprise High Availability Extension product and does not require the addition of a Geo Clustering for SUSE Linux Enterprise High Availability Extension subscription.
General Support Statement
The following definitions apply:
L1: Installation and problem determination - technical support designed to provide compatibility information, installation and configuration assistance, usage support, on-going maintenance and basic troubleshooting. Level 1 Support is not intended to correct product defect errors.
L2: Reproduction of problem isolation - technical support designed to duplicate customer problems, isolate problem areas and potential issues, and provide resolution for problems not resolved by Level 1 Support.
L3: Code Debugging and problem resolution - technical support designed to resolve complex problems by engaging engineering in patch provision, resolution of product defects which have been identified by Level 2 Support.
Novell will only support the usage of original (unchanged or not recompiled) packages.
Read the READMEs on the CDs.
Get detailed changelog information about a particular package from the RPM:
rpm --changelog -qp <FILENAME>.rpm
<FILENAME>. is the name of the RPM.
Check the ChangeLog file in the top level of CD1 for
a chronological log of all changes made to the updated packages.
Find more information in the docu directory
of CD1 of the SUSE Linux Enterprise High Availability 11 Service Pack 2 CDs. This directory includes PDF versions
of the SUSE Linux Enterprise High Availability 11 Service Pack 2 startup and preparation guides.
http://www.novell.com/documentation/sles11/ contains additional or updated documentation for SUSE Linux Enterprise High Availability 11 Service Pack 2.
Visit http://www.novell.com/linux/ for the latest Linux product news from SUSE/Novell and http://www.novell.com/linux/source/ for additional information on the source code of SUSE Linux Enterprise products.
Thanks for using SUSE Linux Enterprise Server in your business.
The SUSE Linux Enterprise 11 Team.